AT517407B1 - Laser unit with collimator adjustment device - Google Patents

Abstract

In a laser unit (11) for a vehicle headlight, the laser diode (12) is associated with an adjustable collimator optics (13) for the laser light emitted by the laser diode (12). The collimator optics (13) comprising at least one optical component, e.g. a lens (14), is arranged in the longitudinal direction (x) arranged in an adjustable by an adjustment device (20) distance from the laser diode (12). The adjusting device (20) comprises a carrier (24) which is adjustable relative to the laser diode (12) by means of longitudinal adjusting means (21) along the longitudinal direction and in which the optical component (14) in a holder (23) transversely to the longitudinal direction (x ) is pivotally mounted.

Description

description

LASER UNIT WITH COLLIMATOR ADJUSTMENT DEVICE

The invention relates to a laser unit for a vehicle headlamp with a laser light source, preferably laser diode, a bearing housing in which the laser light source is mounted, and an adjustable collimator optics for emitted from the laser light source laser light, wherein the collimator comprises at least one optical component, the in a distance along a longitudinal direction to the laser light source is arranged.

For purposes of this disclosure, optical device means an optical component having light-gathering or scattering properties, and more specifically, a shape reflector (e.g., a hollow or convex mirror) or an optical lens, and combinations of these components may be included. The longitudinal direction is understood to mean the direction of the imaginary axis along which the light propagation of the laser light from the laser light source to the collimator optics takes place.

The use of laser light sources in motor vehicles, especially for headlights of motor vehicles, is currently gaining in importance, as laser diodes allow more flexible and efficient solutions, whereby the luminance of the light beam and the light output can be significantly increased.

In the known solutions, however, the laser beam is not emitted directly from the lighting device or the headlight to avoid endangering the eyes of humans and other living beings by the extremely concentrated light beam high power. Rather, the laser beam is directed to an intermediate conversion element containing a material for luminescence conversion, called "phosphor" for short, which converts the laser light, for example a wavelength in the blue region, into visible light, preferably white light, which becomes visible light In the context of the present invention, "phosphor" is understood in general to mean a substance or a mixture of substances which converts light of one wavelength into light of another wavelength or of a wavelength mixture, in particular "white" light, which is also below Term "wavelength conversion" is subsumable. In most cases, the conversion element is preceded by a programmed pivotable mirror (with respect to the beam path of the laser light), by means of which the laser beam can be directed to different locations on the planar conversion element. In order to achieve that on the conversion element well-defined light spots or (with a moving mirror) light pattern are generated, the light originating from the laser light source is collimated by means of an optical arrangement, which is referred to here as collimator optics. The collimator optics are typically located immediately after the laser light source (with respect to the beam path) and may include multiple optical components and / or light-limiting components, but is often formed by a single optical lens.

Due to production-related deviations of the relative position and orientation of the components of the collimator and laser light source, but also to possibly allow later readjustment, it is necessary to adjust the optical components of the collimator relative to the laser light source so that a point of light with the desired sharpness can be generated the conversion element.

In KR 20020054654 A, a laser module with a collimator lens is shown, wherein the collimator lens is pivotally mounted about two axes.

US 5,381,438 A shows a laser module with a collimator lens, wherein the collimator lens is axially adjustable.

In US 5 113 291 A, a laser scanner module is shown with a collimator lens for laser printer, wherein the collimator lens in its axis position is displaceable and adjustable in focus.

It is therefore an object of the invention to allow an accurate and at the same time uncomplicated adjustment of the collimator optics. It has been shown that it is advantageous to allow not only adjustment of the alignment, but also the distance of the optical component (s) of the collimator optics to the laser light source. In particular, in laser modules with multiple laser light sources, an individual adjustment of the individual laser beams is required.

This object is achieved according to the invention, starting from a laser unit of the type mentioned by an adjusting device associated with the collimator with a carrier which is adjustable along the longitudinal direction relative to the laser light source, wherein the at least one optical component within the carrier at least one is mounted pivotally to the longitudinal direction transverse spatial axis.

This solution results in a simple and reliable adjustment possibility of the collimator optics both along the longitudinal direction and transversely thereto, which is also possible after the assembly of the optical system (laser light source, collimator optics, further mirrors, etc.). In this way it is possible to set the lighting technology extremely important, but very sensitive to deviations alignment of the collimator with respect to the laser light source and correct incorrect settings. So far, often expensive assembly cycles can therefore be avoided. Another advantage is the large adjustment range, which provides this technical solution.

In a favorable development of the invention can be provided along the longitudinal direction adjustable longitudinal adjusting device in the bearing housing, wherein the carrier is supported against the at least one longitudinal adjusting means. In this case, in one of the possible advantageous embodiments, the longitudinal adjusting device can be realized as a number of adjusting screws running parallel to the longitudinal direction. In order to keep a later misadjustment, the longitudinal adjusting device can additionally be fixed in its longitudinal position. In addition, it may be expedient if at least one elastically deformable spring element is provided in the bearing housing, with which the carrier is pressed against the at least one longitudinal adjusting means.

In many embodiments, a simplification of the construction of the laser unit can be achieved in that the carrier in the bearing housing along the longitudinal direction adjustable, while the laser light source is firmly positioned in the bearing housing.

In order to achieve greater flexibility of the optical adjustment options, it may be advantageous if the at least one optical component is pivotally mounted about two spatial axes, wherein the mutually perpendicular spatial axes are perpendicular to the longitudinal direction.

In an advantageous embodiment of the invention with regard to the realization of the pivoting of the collimator optics can be provided that in the carrier a holder in which the optical element is held, and at least one attacking on the holder lever - preferably two - are provided, wherein at an outer end of the or each lever, a support means mounted in the support means is provided, with which the lever is adjustable with respect to its pivot position.

It may also be provided that in each case an elastically deformable spring element between a lever and a counter surface of the carrier is arranged and the at least one lever is pressed in each case by an adjusting means, preferably an eccentrically extending screw on the spring element against the counter surface.

Furthermore, it can be provided that the lever is connected to the associated actuating means via a hinge connection, wherein the hinge connection between an end face of the actuating means and a touching contact surface of the lever is formed, wherein preferably the end face and / or the contact surface as are formed spherically curved contact surface.

In order to prevent later deviations of an adjustment once reached, the or the adjusting means may additionally be determined rotatable.

In addition, it can simplify the production, when the holder and the at least one lever are integrally formed with each other.

The invention is particularly suitable for a laser module with a plurality of laser units of the type described above, as well as for a vehicle headlight, in particular for motor vehicles, with a laser unit or a laser module as described above.

The invention together with further developments and advantages will be explained in more detail below with reference to an embodiment which is shown in the drawings and relates to a laser unit with a laser diode in a laser module for a motor vehicle headlight. The drawings show in schematic form: [0022] FIG. 1 a view of a laser unit in a laser module according to the embodiment example, with respect to the outside of the laser unit, via which the adjusting components are accessible; Fig. 2 is a sectional view of the laser unit according to the section A-A of Fig. 1; FIG. 3 is a perspective view of the adjusting device of the laser unit; FIG. FIG. 4 is a perspective view of the carrier in the adjustment device of FIG. 3 with a lens holder; FIG. FIG. 5 shows a variant of the lens holder; FIG. and FIG. 6 shows a headlight with the laser module of FIG. 1.

Referring to Figs. 1 and 2, a laser module 10 includes one or more laser units 11 each having a laser light source 12 formed in the user shown as a laser diode; however, other laser sources of known type are usable in a corresponding manner. The laser units 11 are lined up, for example, in the laser module 10 along a Abstrahllichtweges 19 side by side, in which the light emitted from the laser unit 11 by a belonging to her Abstrahlöffnung 15 light via a mirror 16 is coupled.

The laser light source 12 is associated with a collimator optics 13, which is realized in the illustrated embodiment by a single converging lens 14 (collimator lens) and is arranged in the beam path immediately after the light source 12. The beam path from the laser light source 12 to the collimator optical system 13 runs along the longitudinal direction x in the sense of the invention (vertical in FIG. 2). The emission opening 15 and the mirror 16 are in the embodiment also in the (extended) longitudinal direction x.

Fig. 1 shows the outside of the laser unit 11. In the middle of the laser unit 11, the laser diode 12 is inserted, wherein in the figure, the electrical connections of the laser diode can be seen. On the outside, one or more heat sinks 17 may be applied; in the illustration of FIG. 1, the cooling fins of the heat sink 17 are shown shortened for the sake of clarity. The heat sink 17 has, in addition to an opening for the already mentioned electrical connections of the laser diode 12 further openings, by the adjusting components of the adjusting device according to the invention, namely in the illustrated embodiment, the heads of adjusting screws 21, 31, 41 are accessible from the outside. In addition, first fastening screws 45, with which the laser unit 11 is mounted in the housing of the laser module 10, and second fastening screws 18 for fixing the heat sink 17 can be seen.

2, the adjusting device 20 according to the invention for the collimator optics 13 in a longitudinal sectional view of the laser unit 11 can be seen. In particular, the laser unit 11 comprises a lens holder 23 which holds the lens 14, adjusting members (set screws) 21, 31, and spring elements 22, 32, 42 associated therewith, a holder 24 for the lens holder, and a bearing housing 27 with the lens holder The lens holder 23, in which the collimator lens 14 is inserted, is pivotably supported in the carrier 24, which in turn is slidably supported in the bearing housing 27 along the longitudinal direction x. The carrier 24 is composed of two components of disc-like basic shape, namely a front part 25 and a back part 26th

Referring to Figures 2 and 3, the bearing housing 27 has the basic shape of a cup whose bottom (Figure 1) faces outwardly and which has a flange 28 with a e.g. parallelepiped formation (Fig. 3) added, preferably integrally formed, is. The bearing housing 27 is placed on the side of the cup corresponding side of a - designated by reference numeral 29 - support surface of the housing of the laser module 10, whereby the bearing housing 27 is closed with the carrier 24 housed therein from the support surface (as by a lid). By means of the flange 28, the bearing housing 29 can be secured to the support surface 29, e.g. be screwed on the four ends by means of the fastening screws 18a. Through the support surface 29, the above-mentioned radiation opening 15 of the laser unit 11 runs.

The position of the carrier 24 along the direction x is set in the bearing housing 27 by longitudinal adjusting means, which are designed as two adjusting screws 21 in the embodiment shown. The adjusting screws 21 are arranged parallel to the longitudinal direction x and opposite to each other with respect to the position of the laser diode 12. The heads of the adjusting screws 21 are accessible on the outside (Figure 1) of the laser unit, so here e.g. Hex key or other suitable tool can be set to adjust the adjustment screws 21 to a desired position of the longitudinal direction x. The adjusting screws 21 act on the carrier 24, more precisely on the outside of the back portion 26 of the carrier 24. The carrier 24 is by rubber springs 22, namely between him on the end face of the end portion 25 (see Fig. 3) - and the support surface 29 are arranged, pressed against the adjusting screws 21. As a result, the carrier 24 is biased against the housing, it is always supported on the end surfaces of the adjusting screws 21, and a game of the carrier 24 is avoided. The longitudinal adjustment according to the embodiment shown allows a total displacement in the order of about ± 1 mm.

In Fig. 4, the lens holder 23 is shown with the associated adjusting means; the carrier 24 is opened, namely with removed front part 25, so that only the back part 26 is shown.

Referring to Figs. 2 and 4, the lens holder 23 has a central body 30, the outer shape of which is a ring with spherical outer surfaces. The collimator lens 14 is inserted into the body 30, namely, in a recess of the body opposite to the side through which the laser light source 12 emits the light toward the lens holder; the lens may be in the recess e.g. be fixed by gluing. The carrier 24 has a hollow spherical cavity into which the body 30 of the lens holder 23 is received, so that the latter is mounted in the carrier 24 in the manner of a ball joint.

In the back part 26, two adjusting means 31,41 are provided, through which the lens holder 23 and thus held therein collimator lens 14 - can be pivoted about a respective zugeordnete spatial axis which is transverse to the longitudinal direction. In the embodiment shown, each of the two adjusting means is designed as an adjusting screw 31, 41, which are arranged parallel to the longitudinal direction eccentrically to the position of the collimator lens 14. The heads of the adjusting screws 31, 41 are guided through the bearing housing 27 and thus accessible on the outside (FIG. 1) of the laser unit, so that the adjusting screws 31, 41 can be adjusted to a desired position by means of a suitable tool.

The set screw 31 is for adjusting the pivotal position of the collimator lens 14 about a first transverse axis, the y-axis; the adjusting screw 41 serves to adjust the pivotal position of the collimator lens 14 about a second transverse axis, the z-axis.

The adjusting screw 31 acts on a lever 33 which extends transversely from the axis of light propagation from the body 30 of the lens holder 23, and pushes it over a rubber spring 32 against an inner counter surface 34 (Fig. 2) in the front part 25 of the Carrier 24. This rubber spring is preferably formed as a flat rubber ring, which additionally allows, within the rubber ring (ie in the inner opening) form an elevated stop surface 35, which may preferably be formed obliquely, as a parallel and thus planar stop to the end position of To act levers, see Fig.2. It is advantageous if the end face of the screw 31 and / or the associated contact surface of the lever 33 is curved, for example, spherically curved; In this way, at the point of contact of these two surfaces results in a defined joint. By the action of the rubber spring 32, the lever is biased against the carrier; a game between screw 31 and lever 33 avoided.

The set screw 41 acts on a lever 43 which extends from the body 30 of the lens holder 23 in a direction other than the lever 33; the levers 33 and 43 are preferably arranged offset from one another by 90 ° about the longitudinal axis. The lever 43 is pressed by a rubber spring 42 against the inner counter surface 34. Incidentally, what has been said about the lever 33 applies to the lever 43 in an analogous manner.

The axis of rotation is defined in each case by the extension of the center point of the ball joint to the support point of the adjusting means 31,41 at the end of the respective associated lever 33, 43 of the lens holder 23. These axes of rotation correspond to the axes y and z of Fig. 4. With the screws 31,41 adjusting the pivot position by a total of ± 1.5 ° is possible. The accuracy is, for example, 0.5 ° per revolution; more preferably 0.1 ° per revolution.

Fig. 5 shows a variant of the lens holder with modified levers 36, 46 and modified body 38 of the lens holder 39. Since the levers 36, 46 are pivoted in the rotation of the other lever 46, 36, these are like shown in Fig. 5 advantageously provided with curves 37, 47, which for each position an equal pressure point of the counter surface 34 is acted upon. In addition, a cylindrical extension 44 may be formed on the body 38, which is mounted correspondingly in the carrier (not shown). Both modifications shown in Fig. 5 allow a more fluid pivoting about the two axes of the levers 36, 46th

The adjustment process of the collimator 13 by means of the adjusting device 20 according to the invention, for example, as follows. The laser light source 12 is activated and the light spot (laser spot) generated on the target surface (i.e., the above-mentioned programmed pivotable mirror or phosphor conversion element, respectively) is observed. In general, the laser spot is located outside of the destination required for operation in the center of the target area and is also defocused. First, by adjusting the set screws 31 and 41, the position of the laser spot is changed until the laser spot is at the target location, which typically has a dimension of a few millimeters (e.g., 2-3 mm). Then, the collimator optics are displaced in the longitudinal direction x by means of the adjusting screws 21 until the laser spot on the associated target surface is focused as required. For adjustment, for example, a gauge may be used which includes a sensor arranged to correspond to the target location thus providing a return value for the adjustment described above. As part of the assembly, the intended for the destination optical element is then positioned.

If desired, the adjusting means 21, 31,41 can be permanently determined after adjusting the collimator lens or lens 13, 14 in the set position. This can be done, for example, by clamping the screw head or by applying a thermosetting adhesive around the screw head.

The laser module 10 with the collimator optics 13 thus set can then be inserted into a headlight 9 - shown in FIG. 6 in a partially cutaway view - at the position provided for this purpose.

It should be emphasized that the embodiment is for the purpose of illustration and not to be construed restrictive. Thus, e.g. Instead of the screws other suitable devices for mechanical or electro-mechanical adjustment by hand and / or be provided by servomotors. In a variant in which a pivoting of the lens about only one axis is sufficient, instead of a ball-joint-like configuration, a rotary joint can also be used. Also, in other embodiments of the invention, the collimator optics embodied by a (single) lens in the embodiment shown above may be implemented using multiple lenses, one or more mirrors, or a combination of such optical components. Furthermore, the spring elements can be realized as rubber springs or other elastic components, such as e.g. Spiral or leaf springs. In general, numerous modifications and developments are possible within the scope of the invention, which the person skilled in the art can easily find.

Claims (14)

claims 1. laser unit (11) for a vehicle headlight with a laser light source (12), preferably laser diode, a bearing housing (27) in which the laser light source (12) is mounted, and an adjustable collimator (13) for the laser light source (12) emitted Laser light, wherein the collimator optical system (13) comprises at least one optical component (14) which is arranged in a longitudinal direction (x) extending distance from the laser light source (12), characterized by an adjusting device (20) associated with the collimator optics (13) a carrier (24) which is adjustable along the longitudinal direction (x) relative to the laser light source (12), wherein the at least one optical component (14) within the carrier (24) about at least one spatial axis (y, z ) is pivotally mounted. 2. Laser unit according to claim 1, characterized in that in the bearing housing (27) is provided along the longitudinal direction adjustable longitudinal adjusting device (21), wherein the carrier (24) against the longitudinal adjusting device (21) is supported. 3. Laser unit according to claim 2, characterized in that the longitudinal adjusting device (21) as a number of parallel to the longitudinal direction (x) extending adjusting screws is formed. 4. Laser unit according to claim 2 or 3, characterized in that the longitudinal adjusting device (21) is additionally detectable in its longitudinal position. 5. Laser unit according to one of claims 2 to 4, characterized in that in the bearing housing (27) at least one elastically deformable spring element (22) is provided, with which the carrier (24) against the longitudinal adjusting device (21) is pressed. 6. Laser unit according to one of the preceding claims, characterized in that the carrier (24) in the bearing housing (27) along the longitudinal direction adjustable, but the laser light source (12) in the bearing housing (27) is fixedly positioned. 7. Laser unit according to one of the preceding claims, characterized in that the at least one optical component (14) about two spatial axes (y, z) is pivotally mounted, wherein the mutually perpendicular spatial axes perpendicular to the longitudinal direction (x). 8. Laser unit according to one of the preceding claims, characterized in that in the carrier (24) has a holder (23) in which the optical element (14) is held, and at least one lever acting on the holder (33, 43), preferably two, are provided, wherein at an outer end of the or each lever (33, 43) in the carrier (24) mounted adjusting means (41, 31) is provided, with which the lever (33, 43) with respect to its pivot position is adjustable. 9. laser unit according to claim 8, characterized in that in each case an elastically deformable spring element (32, 42) between a lever (33, 43) and a counter-surface (34) of the carrier (24) is arranged and the at least one lever (33, 43) in each case by an adjusting means (31, 41), preferably an eccentrically extending screw, via the spring element (32, 42) against the counter surface (34) is pressed. 10. Laser unit according to claim 8 or 9, characterized in that the lever (33, 43) with the associated adjusting means (31,41) is connected via a hinge connection, wherein the articulated connection between an end face of the actuating means (31,41) and a this contacting contact surface of the lever is formed, wherein the end face and / or the contact surface are preferably formed as a spherical curved contact surface. 11. Laser unit according to one of claims 8 to 10, characterized in that the / the adjusting means (31,41) is additionally rotatably fixed / are. 12. Laser unit according to one of claims 8 to 11, characterized in that the holder (23) and the at least one lever (33, 43) are integrally formed with each other. 13. Laser module (10) comprising a plurality of laser units (11) according to one of the preceding claims. 14. Vehicle headlight (9) with a laser unit (11) and / or a laser module (10) according to one of the preceding claims.